maintenance of pavement skid resistance (open … · - sistance and struczural performance of open...
TRANSCRIPT
MAINTENANCE OF PAVEMENT SKID RESISTANCE (OPEN GRADED ASPHALT FRICTION COURSES)
RESEARCH PROJECT HR-170
BERNHARD H n ORTGIES, P,E, OFFICE OF MATERIALS
IOWA DEPARTMENT OF TRANSPORTATION
APRIL 1976
T a b l e o f C o n t e n t s
I n t r o d u c t i o n
O b j e c t i v e s
E v a l u a t i o n Approach
P e r t o r m a n c e
C o n c l u s i o n s
Bib1 ~ o g r a p h y
T a b l e 1 - R e s e a r c h O b ? e c t l v t s
I T a b l e 3 - ?l ix D e s i g n R e p o r t
T a b l e 4 - Mix D e s i q n R e p o r t
T a b l e 5 - " i x D e s l q n Repor t
? a x e 5 - Mix D e s i g n R e p o r t - -
T a b l e 7 - Mlx D e s i g n R e p o r t - T a b l e 5 - A g g r e a a t e Data
T a b l e 9 - C o m p a r i s o n o f G r a d a t i o n T e s t s
T a b l e 1 0 - L a b o r a t o r y T e s t D a t a
T a b l e 1 1 - S k i d Resis :ance R e s u l t s
T a b l e 12 - Aspha1.t T e s t R e p o r t
Appendix A - T e s t S e c t l o n P l a n
A a ~ e n d l x B - S l t e ?:an
P a g e
1
1
2
6
2 2
2 4
2 5
2 6
27
2 8
2 9
3 0
3 1
3 2
3 3
3 4
3 5
3 6
3 7
3 8
- 1 -
I NTRODCCTION -- -- Dry pavements seldom oEfer inadequate skid resistance to a
rollin9 or sliding motor vehicle tire. The formation of a film
of w ~ t e r between the tlre and pavement surface dramatically
chancics the physical lnteractlon that normally takes place.
Evcn urcater chdnaes take p l ~ c e when the vehicle is required
to make siqnificant adjustments in direction or speed. Numerous
studies have been made in an effort to measure the skid resis-
tance, skid resistance requirements, tire characteristics, and
other related parameters. These stud~es caused the Federal
Hiqhway Administratiol, to develop certain design criteria (1)
and denonstration f>rocedures ( 2 ) for field trials and evalua- - tLons by the states. This report documents the Iowa Department
F f Transportation's activity on such a project designed to eval-
uate one type of asphalt pavement surface that has, on occasion,
shovn that it can provide superior skld resistance when wet.
When first developed, this surface was called "Plant Mix Seal
Coat" because of its resemblance to chip seals commonly in
use: throuch development and usage it has been renamed "Open
Graded hzphalt Friction Course".
-OBJECTIVES
Previous studies havc shown that the characteristics of
the agcregate ar.d the desiqn of the nix determine the skid re-
sistance and struczural performance of Open Graded Asphalt Fric-
- ticn Course mixes. Ge~erally, aggregate selection for other
types of pavement and uses is heavily influenced by availability
znc? cost. Slnce the quantltles of aggregate are siqnificantly
reduced through Open Graded Asphalt Friction Course construction,
- 2 -
! c ~ : i s t l c a l problems associated with long distance shipping and
h ! c h c r unit ccsts could be ju~tified on at least some high priority
s.ifety projects if this type of construction proves to be suffi-
c:enrly superior. The major objectives of this project involve
the cvaluatlon of several agqreqates previously rated poor to ex-
ccllcnt wlth respect to skld :eslstance and certain mix deslgn
jaraneters. Detailed lists of these objectives, divided into
three qroups, are cnntalned in Table 1.
EVhL.CXTIO?i APPROACH
Pro5ect information. To attain the objectives listed in Table 1,
the Iowa Department of Transportation, as the Iowa State Highway
Corrlsslon, developed Research Project HR-170 on the recommenda-
tion of the Iowa Highway Research Board and with approval of the
Federal Ilighway Administration. A construction contract (Story
County F?:-69-S(15)--21-85) was entered into with the Iowa Road
Builders Company to construct ten test sections of Open Graded
Asphalt Friction Course on US 69 north of Ames. Construction of
the two and one half (2-1/2) miles of test sections began on
July 15, 1974 and was completed on July 17, 1974. An as-built
listing of the test sections is provided in Table 2 and a layout
is nrovided in Appendix A.
The 2-1/2 miles of test sections are subjected to primary
road traffic comparable to many miles of road around the state
adjacent to urban areas. The Iowa DOT traffic records indicate
the 1974 Average Daily Traffic (ADT) is 4050 VPD. Approximately
5.5 percent of these vehicles are trucks.
thl-k conrtructe(-1 in 1957 and asphalt concrete surfaced P.C. coil-
crete pavement. The latter section of pavement had originally
been constructed in 1931, widened in 1955, and resurfaced in 1957.
Test Section Number 1 and part of Test Section Number 2 were con-
structed over the bare P.C. concrete pavement; the remaining sec-
tions (part of 2, and 3 thru 10) were constructed over the pave-
ment resurfaced with asphalt concrete.
The desigii,construct~?n, subsequent testlng, and evaluations
of the test sections generated considerable data. Mix design re-
sults are listed in Tables 3 through 7; project control test data
are summarized in Tables 8, 9, and 10. Skid test data are listed
in Table 11. All measulaments and tests were performed per re- - quirements of the Standard Specifications ( 3 ) and applicable In-
structional Memorandums ( 4 ) (5).
Materials. The project was set up to evaluate the Open Graded
Asphalt Friction Course using four comparably graded aggregates;
quartzite, fine grained limestone, coarse grained limestone, and
lightweight expanded shale. Source information and properties
are provided in Table 8. These materials were selected because - they represent the range of crushed aggregate characteristics
normally available to the Iowa DOT.
Quartzite has a good performance history in conventional
pavements and has a l w been extensively and satisfactorily used
for filter stone and railroad ballast. Quartzite and traprock
have been considered the best materials available. Usage though,
2 traprock) are located in the state.
Calcerous and dolomitic limestones of varying quality and
texture-grain size are available locally over much of the state;
coarse and fine grained limestone aggregates were therefore in-
cluded in this project. Performance of the materials in pave-
ments and structures can vary considerably and they therefore
must be carefully selected and processed. Generally, limestone
agqregates ic asphalt surface courses have been found to polish
quite rapidly and contribute to low skid resistance values.
The polish-rate or SS loss can generally be correlated to traf-
fic vo1w.e and aqqregate texture or grain size. -L
Expanded shale-liqhtwei~ht aggregate, available from three - qgurces :one in Iowa) was selected because it has been used ex-
:ezsivcig by other states in open and dense graded asphalt mix-
tcres to icprove skid resistance. It has the advantage of being
s:c~~ifica~tly lighter and thus less costly to ship. If it can
Sf sb.ot;n tc resist studded tire wear (it may be possible to pro-
tect tF.2~ material through blending) and otherwise exhibit satis-
factory perfomance, it might become a viable alternative on some
projects. - Asphalt bir.der material used throughout on this project was
85-100 penetration asphalt complying with the requirements of
hASH'iU) Specification M-20. The properties of the material are
shown in Table 12. -
e v e n t f u l . The c o n t r a c t o r a r r a n g e d t o h a v e a l l o f t h e m a t e r i a l s
o n hand a t t h e p l a n t s i t e and was q u i t e w e l l o r g a n i z e d . E x c e p t
f o r l o w e r i n g t h e m i x i n g t e m p e r a t u r e , o n l y a few r a t h e r i n s i g n i -
f i c a n t o p e r a t i o n a l a d j u s t m e n t s w e r e n e c e s s a r y . The c o n t r a c t o r
u s e d a c o n v e n t i o n a l Cedar R a p i d s B a t c h P l a n t e q u i p p e d w i t h a
B a r b e r G r e e n e d r y e r , c o l d f e e d e r , and p o l l u t i o n c o n t r o l u n i t .
A Cedar R a p i d s p a v e r e q u i p p e d w i t h a v i b r a t o r y s c r e e d was u s e d
t o p l a c e t h e m a t e r i a l . 'I;:? mix was cornpacted w i t h s t a n d a r d s tee l
t i r e d ( s t a t i c t y p e ) r o l l e r s . Compac t ive e f f o r t was c o n t r o l l e d
w i t h a s i m p l e p r o c e d u r a l s p e c i f i c a t i o n ( 3 ) .
i o w e r i r q t h e m i x i n g t e m p e r a t u r e t o p r e v e n t d r a i n a g e o f t h e
a s p h a l t cement d u r i n g h a u l i n g and p l a c i n g o p e r a t i o n s w a s o u n d
n e c e s s a r y on p r e v i o u s p r o j e c t s . Normal ly , a s p h a l t m i x t u r e s are
produced a t t e m p e r a t u r e s r a n u i n q from 250°E' (121°C) t o 325Of
i lE3OC). Because t h e O?en Graded F r i c t i o n C o u r s e m i x t u r e s a r e
e x t r e n e l y o?en g r a d e d ar.6 c o n t a i n few f i n e s ( m i n u s Z O O ) , t h e
v i s c o s i t y o f t h e b l - d e r ~ u s t b e r e d u c e d t o p r e v e n t m i g r a t i o n
and d r a i z a g e . The t e n p e r a t u r e r a n g e found s a t i s f a c t o r y f o r
r . --,p,. -i-.. ..* .L ,..ese z i x t c r e s i s 20CoF ( 9 3 O ~ ) t o 250°E' (121oC) .
- .':r e x a r t t e r ? e r a t c r c f ~ r a ::,:en n i x t u r e n u s t b e se t on t h e
.-'- - a'c. -.- . .- . . - ....? -..-, accx.- . t s~:c>, s a r a r c t e r s a s w e a t h e r , h a u l d i s -
- a - - e . a,;jre;z:e c . - . a rac te r : a t : c s , an? b i n d e r p r o p e r t i e s . F o r
CXL-;le. :: i.ss fr?:r.d :?.a: t k e s u a r t z i t e n i x u s e d o n T e s t S e c -
-, -- - . . - - . .s 5 a-2 1: :,---: be rrcdsctr-? a s low a s 2 0 0 ~ ~ ( 9 3 O ~ ) and y e t
bd :.;-clef satlsfa:ccr::... . i.. : -:-o . a . I t s h o u l d b e n o t e d t h i s
-..- -:,e cf 7 : x t c r e .cx:s x i t e r a a : d l y and t h e r e f o r e c a n b e d i f f i -
z:: tc ; l a c e 51. ha:.? :et?.*s. D e l a y s and c o o l w e a t h e r c a n f u r -
-'. ---- , . - % * e -.. e . . - r - a ~ e ? e r . : and s h o s l d t h e r e f o r e b e a v o i d e d .
The performance f f i e l d tes t s e c t i o n s must always b e eva lu -
a t d d i n l i g h t of t h e wide v a r i e t y of v a r i a b l e s found i n t h e f i e l d ,
a s opposed to l a b o r a t o r y s t u d i e s wFich can be performed under more
i d e a l c o n d i t i o n s w i t h t h e v a r i a b l e s i d e n t i f i e d and c o n t r o l l e d .
The r e s u l t s and conc lus ions t h a t p r e c i p i t a t e from f i e l d e x p e r i -
ments may b e unduly in f luenced by u n c o n t r o l l e d o r u n i d e n t i f i e d
v a r i a b l e s and t h e r e f o r e must be more c a r e f u l l y drawn. I n some
c a s e s , t h e conc lus ions must be q u a l i f i e d cr postponed because t h e
t r i a l s have n o t run long ei.?>.gh t o cause t h e a c t l o n s and i n t e r -
a c t i o n s t o s e t o u t o b s e r v a t i o n s which c l e a r l y set t r e n d s o r g i v e
cause t o c o n c l u s i o n s . Each of t h e o r i g i n a l p ~ j e c t o b j e c t i v e s
(Table 1) has been examlned i n l i g h t of t h e d a t a c o l l e c t e d and
i n each c a s e , a s o u t l i n e d above, a d e t e r m i n a R o n has been made.
The " o v e r a l l performance" of t h e t e n tests s e c t i o n s of Open
Graded F r i c t i o n Course a f t e r 16 months o f s e r v i c e can be c l a s s i -
f i e d i n t o good and poor c a t e g o r i e s . G e n e r a l l y , bond, m a t e r i a l
wear, mix tu re d u r a b i l i t y , and s k i d r e s i s t a n c e o f a l l of t h e mixes
must be r a t e d good. Performance o f a l l of t h e mixes over and ad-
j a c e n t t o c r a c k s and j o i n t s i n t h e o l d pavement must be r a t e d
poor. Ex tens ive r a v e l i n g and a b r a s i o n of t h a s u r f a c i n g over and
a d j a c e n t t o c r a c k s and j o i n t s i s t a k i n g p l a c e ; t h i s no t o n l y i s
s e v e r e l y d e t r a c t i n g from t h e appearance , b u t is very q u i c k l y re-
s u l t i n g i n numerous non-uniform a r e a s of d r i v i n g s u r f a c e . F i e l d
o b s e r v a t i o n s d u r i n g pe r iods of inc lement weather a l s o i n d i c a t e
t h a t snow and i c e c o n t r o l o p e r a t i o n s a r e somewhat more d i f f i c u l t
t o handle on t h e tes t s e c t i o n s a s compared t o t h e dense graded
a s p h a l t c o n c r e t e pavement l o c a t e d t o t h e n o r t h and t h e P.C. Con-
- 7 - Research Objectives - Group I. Objective A involves, in part,
the verification of observed performance demonstrated by the quart-
zite test sections on the preliminary Woodbury project (6). This
objective also requires a determination, if possible, as to wl~ether
quartzite is indeed a superior polish resistant material as pre-
viously supposed.
Field observations appear to support the claims that quart-
zite is a sound and durable material, because traffic and weather-
ing action have not depreciated the material on the road. Material
loss from the pavement surface can be attributed to raveling of
the mix adjacent to the many cracks that have reflected through
from the old pavement and widening. The skid resistance test
data of the quartzite sections (9 and lo), as shown in Figure 1,
compare favorably with the Woodbury results and indicates that
quartzite when used alone will provide acceptable SN levels.
1:' Figure 1
3 0
0 5 10 15 2 0 25 Age in months
r Woodbury Story
Quartzite
- 8 -
Objective B was designed to evaluate the effect of blend-
1ng the assumed superior quortzlte with a typical coarse grained-
t.extured limestone. Crushed limestones comparable to this one
are available over much of the state, but must be quarried se-
lectively and with proper inspection safeguards. This group of
crushed limestones has generally performed satisfactorily with
respect to soundness and durability, although they have benn
found to pollsh when subjected to heavy traffic for long periods.
Upgradrng by blending may t~~erefore extend usage and longevity.
The blend of quartzite and coarse grained limestone was set up
on en equal ratio basis, i.e. 50 percent quartzite, 50 percent
limestone; each material having comparable gradation. Thus far,
this blend (Test Sections 3 and 4) is performing satisfactorily
with respect to durability. It is also exhibiting, as shown in
Figure 2, an adequate SN history.
I Figure 2
0 5 10 15 2 0 25 Age in months
50/50 Blend of Quartzite L coarse grained limestone I
p h a l t F r i c t i o n Course u s i n g t h e p r e v i o u s l y d e s c r i b e d c o a r s e g r a i n e d
l imestone f o r a g g r e g a t e . A s mentioned above, t h i s m a t e r i a l h a s
been used s u c c e s s f u l l y , i n a s p h a l t c o n c r e t e m i x t u r e s and is a v a i l -
a b l e l o c a l l y i n many a r e a s . I t t h e r e f o r e needed t o be e v a l u a t e d
i n t h i s type of mixture . Based on t h e f i e l d t r i a l i n T e s t Sec-
t i o n s 5 and 6 , it would appear t h a t t h i s m a t e r i a l w i l l perform
I s a t i s f a c t o r i l y w i t h r e s p e c t t o d u r a b i l i t y and, t h u s f a r , t h e r e
I does n o t appear t o be any i n d i c a t i o n t h a t it w i l l wear e x c e s s i v e l y .
I The l a t t e r concern must be a p p r e c i a t e d i n terms of aggrega te hard-
i n e s s and minera logy, t r a f f i c volumes, and s tudded t i re usage. A l l
pavement s u r f a c e s and m a t e r i a l s wear somewhat, b u t t h e a g g r e g a t e s -.-
i n open graded mixes, due t o t h e l a c k of s u p p o r t i n g m a t r i x , a r e
p o t e n t i a l l y s u b j e c t t o more t h a n average wear. The SN d a d ,
shown i n Figure 3 , appear to b e more v a r i a b l e and somewhat lower
on t h e average when compared t o t h e d a t a p r e v i o u s l y p resen ted .
I t has maintained a h igher S N l e v e l than t h e f i n e g r a i n e d l ime-
s t o n e t e s t s e c t i o n s c o n s t r u c t e d i n Black Mawk County ( 7 ) .
b Black Hawk S t o r y
50.-
SN 40-- / 4
/ \ #
# ,< # \
\ * # \ 30--
- b- "" \
\
F i g u r e 3 b
20 0 I 8 , I
0 5 10 15 2 0 25
Age i n months Coarse Grained Limestone
Percentage of Quartzite/Limestone/SN
12 months - - - - - - - - - _ _ _ 5 o . c
4 months
SN 40--
30 -- Figure 4
2 0 Percentage of Quartzite
100 4 - 0
0 Percentage of Coarse Grained\ Limestone
100
- lo - As a side light, the data obtained from the test sections
constructed for objectives, A , B and C provide an opportunity to
examine the SN performance of two materials separately and in
combination. Figure 4 shows how quartzite and coarse grained
limestone resist polishing after four months and one year of
traffic. It should be noted that the 50/50 blend is composed
of comparably graded aggregates.
- The one year relationship, as is often the case, shows im-
provement in SN level over the shorter four month period. This
can be attributed to weathering and traffic wear of the asphalt
films present on the surface of the new pavement. The longer
- 11 - term t r e n d s w i l l be examined i n t h e a n a l y s i s o f t h e Group I1
O b j e c t i v e s .
Objec t ive D was des igned t o e v a l u a t e t h e performance of a
blend o f q u a r t z i t e and f i n e g r a i n e d l imes tone . The combined ma-
t e r i a l was comprised o f e q u a l p a r t s o f comparably graded m a t e r i a l .
F i ~ u r e 5 shows t h a t t h i s blend p laced on T e s t S e c t i o n s 1 and 2 ,
is a l s o performing s a t i s f a c t o r i l y . The combination g e n e r a l l y ex-
h i b i t s lower S N v a l u e s than t h e p r e v i o u s l y d e s c r i b e d blend of
q u a r t z i t e and c o a r s e g ra ined l imes tone . T h i s was expected be-
cause t h e Black Hawk (7) Open Graded F r i c t i o n Course p r o j e c t i n -
d i c a t e d t h a t f i n e g r a i n e d l i m e s t o n e a g g r e g a t e s , when used a l o n e ,
would n o t provide h igh B K v a l u e s . - - Black Hawk* Story*'
Age i n months '100% Fine Grained Limestone
**50/50 Quar tzf te /Fine-Grained Limestone
Q u a r t z i t e / F i n e Grained Limestone
o l a t i n g t h e d a t a shown i n f i g u r e s 1 and 5 t o v e r i f y t h e conclu-
s i o n drawn on t h e Black Hawk p r o j e c t t h a t f i n e g r a i n e d l imes tone
would e x h i b i t low SN l e v e l s . The FWA (1) e t a1 have recommended
t h a t such m a t e r i a l s n o t be used because t h e y tend t o p o l i s h under
t r a f f i c .
f i g u r e 6 t e n d s t o confirm t h a t t h i s t y p e o f m a t e r i a l d o e s i n
f a c t e x h i b i t lower SN va lues .
- A * F i n e Grained Lirnes tone/Quar tz i te I
6l s t o r y
30t Black Hawk I F i g u r e 6
2 0 I Pe rcen tage of Q u a r t z i t e 0
-entage of F i n e Grained ~ i m e s t o n e A 100
- O b j e c t i v e H was designed to d e t e r m i n e i f an expanded s h a l e
( o r c l a y ) commonly used t o produce l i g h t w e i g h t c o n c r e t e cou ld b e
blended w i t h a f i n e g ra ined l imes tone and the reby o b t a i n improved
SN performance. Expanded c l a y s and s h a l e s have been used by
- s e v e r a l s o u t h e r n s t a t e s i n t h i s way q u i t e s u c c e s s f u l l y . Few
so-rces of t h i s m a t e r i a l a r e a v a i l a b l e t o t h e Iowa DOT; t h i s
o f course can cause t r a n s p o r t a t i o n l o g i s t i c s problems and r e s u l t
i n h igher costs. There i s a l s o some concern w i t h r ega rd t o
whether t h i s aggrega te is s t r o n g enough t o resist studded t i re
fied on this project.
Figures 7 and 8 indicate that this blend (Test Sections 7 and
8) is exhibiting satisfactory SN levels, Roadway examinations in-
dicate that the combination is performing quite well with respect
to wear and durability; surface course material loss thus far ap-
pears to be associated with reflection crack raveling.
Figure 7 3 0 I I
I 1 I 8
0 5 10 15 2 0 2 5 Age in months
Expanded Shale/Fine Grained-Limestone Blend
50/50 Blend I
Fine Grained Limestone I
Figure 8
20 I 100 Percentage of Expanded Shale 0
0 Percentage of Fine Grained Limestone 100
Expanded Shale/Fine Grained Limestone
- 14 - Research Objectives - Group 11
The second set of research objectives, K1, through Kg, in-
volves the evaluation of the effects of traffic on the aggregates
used in the test sections. More specifically, of interest are
the polishing rates determined by plotting the observed skid
numbers versus the cumulative vehicle passes. The resultant
slope K being the polishing rate. It will be noted that such
slopes would be valuable design aids when selecting aggregakes
for projects and for predicting performance.
In evaluating the traffic-SN data for the,test sections on
the project, it was found that not enough time had passed to
accumulate enough data points to establish definite trends. An
example is Figure 9 which displays the polish curve data for
the most polish susceptible agqregate used, i.e. limestone. The
polish curves for the other aggregates indicate similar perfor-
mance behavior and therefore were not included in this report.
. >
. - .. a
-.-< :
.
. .--
Future Data
a
W
.. -
m
=
-- 2
30
K=Slope of line
- y
Measured at 40 Miles per hour
1 I
I I
I
t r
11
1
I I
I
I 1
1 1
1
1 2
5 10
20 50
11 VEHICLE PASSES-MI LLIONS
FIGURE 1-PAVEMENT WEAR (POLISH) CURVES
. - . .
- 16 - ~t would appear from t h e d a t a c o l l e c t e d t h u s f a r and t h e
e r a f f ~ c volumes t h a t a t l e a s t s e v e r a l more y e a r s of exposure w i l l
be r equ i red b e f o r e d e f i n i t e r e l a t i o n s h i p s can be e s t a b l i s h e d . A
follow-up e v a l u a t i o n and r e p o r t w i l l t h e r e f o r e be needed.
Although t h e d a t a does n o t a s y e t i n d i c a t e d e f i n i t e long
term '.:ends, t h e y do i n d i c a t e t h - t c o n s i d e r a b l e t r a f f i c passages
a r e r e q . a r e 3 t o wear t h e asphal t t l l m o f f of t h ~ agqregace such
t h a t t h e n?xjrnvm SY va lues can be r e s t i l e d . O r t h i s p r o j e c t ,
F i g u r c ; 1 througS 9 ~ n d i c a t e t h a t up t o e i r h t ( 8 : mop'hs o r abou t
600,000 v e h l c l e FsSSeS r e k p e c t i v e l y a r e r e q u i r e d t o plexirrize t h e
SN p o t e ~ ~ t i a l . I t wuuld b e reazonab le t o e x 2 e c t t h a t roads wish
h igher t r a f f i c volumes would r e a l i z e t h e maximum S N sooner be-
cause h igher t r a f f i c volumes would wear t h e f i l m s more r a p i d l y .
Research O b j e c t i v e s - Group 111
The f i r s t and second o b j e c t i v e s i n t h i s group invo lve e v a l -
u a t i n g t h e e f f e c t s of a s p h a l t c o n t e n t d i f f e r e n c e s w i t h r e s p e c t
t o t r a f f i c and performance. I n o r d e r t o minimize t h e e f f e c t o f
aggregate g r a d a t i o n , i . e . s u r f a c e a r e a , a l l of t h e mix d e s i g n s
were s e t up w i t h comparable aggrega te g r a d a t i o n t a r g e t v a l u e s .
Two l e v e l s of a s p h a l t c o n t e n t (5.25 and 6.25 p e r c e n t ) were t h e n
set t o provide t h e d i f f e r e n t a s p h a l t c o a t i n g s on t h e a g g r e g a t e
p a r t i c l e s and a i r void l e v e l s . Because t h e expanded shale-l ime-
s t o n e a g g r e g a t e combination had a s u b s t a n t i a l l y lower s p e c i f i c
g r a v i t y t h a n t h e o t h e r a g g r e g a t e t y p e s , t h e a s p h a l t c o n t e n t s f o r
t h i s s p e c i a l aggrega te combination were a d j u s t e d upward (one
p e r c e n t ) t o p rov ide comparable a s p h a l t - a g g r e g a t e r e l a t i o n s h i p s .
S p e c i f i c d a t a f o r t h e v a r i o u s mix tu res a r e con ta ined i n T a b l e s
3 through 7 .
- 17 - f i e l d examinat ions o f t h e tes t s e c t i o n s i n d i c a t e t h a t a f t e r
two w i n t e r s t h e r e appears t o be no r e l a t i o n s h i p between a s p h a l t
c o n t e n t l e v e l s and t r a f f i c w i t h r e s p e c t t o performance. Raveling
type of wear, g e n e r a i wear, and weather ing t o d a t e does n o t appear
t o 5e i ~ f l u e n c e d by a s p h a l t c o n t e n t . While it is p o s s i b l e t o
d i s t i n q l ~ i s h hetween aggrege te t y p e s . S s u a l l y . it i s n o t poss ib l f ;
to d i - s t ingu i sh between t h e a r 2 h a l t c o n t e n t v i sua l i ; r , even thouch
t h e r e is a 19 ? e r c e n t v o l w e t r i ; d i f f e r e . ~ c e .
A det31:ed examination o f t h e s u b s t a n t i a l c?flec"or. c rack-
ing a l s o i n d i c a t e s +.hat a s p h a l t c o n t e l t h a s n o t intluer.-e3 r a v e l -
ing df t h e c r a c k edges. T h i s c r a c k i n g h a s developed over - ~ i r -
t u a l l y a l l o l d j o i n t s , c r a c k s , and p a t c h e s and i s t h e primary - - d i s t r e s s parameter i n ev idence i n a l l t e s t s e c t i o n s . I n addi - - t i o n t o be ing u n a f f e c t e d by a s p h a l t c o n t e n t , t h e r e f l e c t i o n
c rack ing and r e l a t e d r a v e l i n g does n o t appear t o be in f luenced
by aggrega te type .
In view of t h e performance observed t o d a t e , mix d e s i g n
parameters can n o t be d e f i n e d e x a c t l y ; a l though it can b e s a f e l y
concluded t h a t none o f t h e tes t s e c t i o n s e x h i b i t evidence of
over -aspha l t ing . Th i s f i n d i n g i s suppor ted by t h e o b s e r v a t i o n s
t h a t f l u s h i n g , b l e e d i n g , i n s t a b i l i t y o r o t h e r u n s a t i s f a c t o r y - behavior caused by over -aspha l t ing a r e n o t i n evidence on any
t e s t s e c t i o n . Th i s would i n d i c a t e t h a t t h e a s p h a l t f i l m t h i c k -
n e s s and a i r void l e v e l s f o r t h e h i g h e r a s p h a l t c o n t e n t l e v e l - ( 6 . 2 5 % ) can b e used f o r f u t u r e d e s i g n s . The lower a s p h a l t con-
t e n t l e v e l ( 5 . 2 5 % ) used on t h i s p r o j e c t , a l t h o u g h more economical ,
would, based on p a s t performance on o t h e r p r o j e c t s and r e s e a r c h ,
b e cons ide red t o o low f o r good long term performance. Of c o u r s e ,
it w i l l c o n t i n u e t o b e n e c e s s a r y t o e x e r c i s e good judgment, a s
- 18 - is always t h e c a s e , when d e s i g n i n g mixes o f t h i s type. The
primary c h a r a c t e r i s t i c s r e q u i r i n g a t t e n t i o n and c o n s i d e r a t i o n
w i l l c o n t i n u e t o be m a t e r i a l c h a r a c t e r i s t i c s such a s aggrega te
g r a d a t i o n and a b s o r p t i o n , roadway f e a t u r e s , and t r a f f i c .
T:.e th i . rd r e s e a r c h o b j e c t i v e i n t h e g r o c p involved e v a l u a t -
t v - j bond 0 . t h e upen g r a d e d f r i c t i o n c-srse mix tu r? i n T e s t Sec-
t -ons 1 and 2 t~ t h e p o r t l a n d c e n e r t c0ncrel.e pavement. I-here
had been xepn-ta that. t h i s ,ype of mix c o u l d n o t be '9r.ded is-
L - i c t ~ c i l y t o such p.=vemt!nts k i t h o n t f i x s p l a c i n g a new ~ s p h a l t
c o n c r e t e b i n d e r course . I n examining T e s t S e c t i o n s 1 and 2 , i t
was found t h a t a l l of t h e mix was s a t i s f a c t o r i l y bonded e x c e p t
where r e f l e c t i o n c r a c k s and j o i n t s were showing through. Ravel- _ ing a t c r a c k s and j o i n t s was found t o be comparable t o t h a t cS-
served on t h e p rev ious ly o v e r l a i d s e c t i o n s , 3 through 10. Again
mixture a s p h a l t c o n t e n t (5.25% & 6.25%) d i d n o t appear t o a f f e c t
performance w i t h r e s p e c t t o bond or c r a c k r a v e l i n g . It was a l s o
i n t e r e s t i n g t o n o t e t h a t bond on bo th t y p e s of pavement was n o t
a f f e c t e d by t h e v a r i a b l e and subsrandard t a c k c o a t a p p l i c a t i o n
which caused some concern w h i l e work was i n p r o g r e s s .
- 19 -
A r e s e a r c h p r o j e c t des igned t o e v a l u a t e Open Graded Aspha l t
F r i c t i o n Courses is d e s c r i b e d . T.he 2-1/2 m i l e p r o j e c t l o c a t e d
on U.S. 69 n o r t h o f Amer i n S t o r y County involved placement of
t e n (1) tes t s e c t i o n s . Ki;:cs w e r e p l a c e 3 us ing f i v e ( 5 ) aggre -
; a t e combir.%t!.CnS, each a t t w 2 ( 2 ) a s p h a l t r o l t t e n t s . ~~~~~~~~~e of t h e t e s t s e c t k n s was evi . luata6 by Sli t e s t i n g and i i e i d exami-
n & t ions .
The S?' performance of h i 1 t z s t s ~ c t i o n s a t t e r s i x t e e n (16)
months of t r a f f i c exposure was f o u t o be s a t i s f a c t o r y i n t h a t
none of t h e m a t e r i a l combinat ions had po l i she? t o t h e p o i n t where
unacceptable S N l e v e l s developed. When m a t e r i a l ~ p m b i n a t i o n s
were compared, r e f e r t o F i g u r e 10 , s i g n i f i c a n t d i f f e r e n c e s were - noted . Three of t h e test s e c t i o n s , i t is shown, e x h i b i t h i g h e r
S N l e v e l s than t h e a d j a c e n t d e n s e graded 3/8 i n c h Type A A s p h a l t
Concre te s u r f a c e p laced j u s t b e f o r e t h e r e s e a r c h p r o j e c t began.
FIGU
RE 10
SKID N
UMBE
R VS,
AGE
t Section W
end
Description
A*-
50% Quartzite 6 50% FG.
Limestone
1 3
&4
500 Ouartzite 6
. 50% CG. Limestone
100% C.G
. Limestone
50% Expanded Shale 6 50% F.G.
Limestone
!EST
ECT
I ON
19610
100% Quartzite
5 Control
Dense Graded Type A Asphalt Concrete
3 s 10
AGE
- MONTHS
I
Field examinations through the first 20 months of service
indicated that, except where reflection crack raveling was tak-
ing place, all of the mixes were well bonded, resisting wear and
weathering satisfactorily, and did not exhibit obvious sensiti-
vity LO asphalt content. Thus far, the primary distress para-
meter appear: to be crack raveling; some maintenance will be
neeled il the near future because of this. It = ~ u l d be noted
that the aEjacent surfacing placed in 1974 on com.>arable base
will also 5w.r require crack naintenance, althcugh to a lesser
extent..
- 2 2 - CONCLUSIONS
The major o b j e c t i v e s of t h i s p r o j e c t i n v o l v e t h e e v a l u a t i o n
of Open Graded Aspha l t F r i c t i o n Courses u s i n g t h e spectrum of
aggrega tes a v a i l a b l e t o t h e Iowa Department of T r a n s p o r t a t i o n ,
and c e r t a i n mix d e s i g parameters . The fo l lowing conc lus ions
a r e based on t h e performance observed on t h i s p r o j e c t .
1. Open Graded Asphalt F r i c t i o n Courses can be a a t i s -
f a c t o r i l y c o n s t r u c t e d on and bonded t o o l d p o r t l a n d ce-
ment co. C r e t e and a s p h a l t c o n c r e t e bases .
2 . The pr imary d i s t r e s s parameter a f t e r 20 months of
s e : ~ i c e is s u r f a c e r a v e l i n g over and a d j a c e n t t o v i r -
t u a l l y a l l r e f l e c t i o n c r a c k s . -C
Crack r a v e l i n g w i l l r e q u i r e e G l y maintenance, - reduce t h e e f f e c t i v e s e r v i c e l i f e s i g n i f i c a n t l y , and
d e t r a c t s from t h e o the rwise s a t i s f a c t o r y appearance.
4 . Within t h e range o f a s p h a l t c o n t e n t s used on t h i s
p r o j e c t , t h e s e mixes do n o t appear t o b e s e n s i t i v e t o
a s p h a l t c o n t e n t . The performance of a l l of t h e t e s t
s e c t i o n s i n d i c a t e s t h a t f u t u r e mix d e s i g n s should ex-
h i b i t c h a r a c t e r i s t i c s comparable t o t h e 6 .25% Asphal t - Content mixes.
1 5 . Crack r x v e l i n g does n o t appear t o b e a f f e c t e d by
a s p h a l t c o n t e n t o r aggrega te type .
6. The q u a r t z i t e aggrega te a f t e r 2 0 months o f ser-
v i c e a p p e a r s t o develop and main ta in h i g h e r SN v a l u e s
than t h e o t h e r aggrega tes and s i g n i f i c a n t l y i n f l u e n c e s
and improves t h e performance o f a g g r e g a t e b lends .
Bibliography
1. Report No. FHWA-RD-74-2 Desig;~ of Open Graded Asphalt Fric- tion Courses, US Department of Transportation, FHWA Office of Research and Development.
2. Deronstration Projects Program, US Department of Transpor- tation, FHWA Region 15.
3. Standard Specifications, Ser4.e~ 1972, Iowa State Highway Commission as amended hy applicable Special Provisions and Supplemental Specifications, (refer to contrzct documents for specific list).
4. Materials I.M. Manual, Office of Materials, Iowa Depart- ment of Transportation, Ames, Iowa.
5. Laboratory Manual, Office of Materials, Iowa Department of Transportation, Ames, Iowa. -
6. Bernhard H. Ortgies, Special Rejort - Plant Mix Seal Coat Test Section, Woodbury County, w ate rials Department, Iowa State Highway Commission, September, 1973.
7. Bernhard H. Ortgies, Special Report - Plant Mix Seal Coat Test Section, - Black Hawk County, Iowa State Highway Com- mission, September, 1973.
of t h e f i n e g ra ined l imes tone aggrega te . Thus f a r t h e ex-
panded s h a l e - f i n e g r a i n e d l imes tone combination ( T e s t
S e c t i o n s 7 6 8 ) is e x h i b i t i n g h i g h e r SN v a l u e s than t h e
q u a r t z i t e - f i n e g ra ined l imes tone combination, ( T e s t
S e c t i o n s 1 h 2 ) .
9. The second b e s t S N performance curve is provided by
t h e q u a r t z i t e - c q a r s s g r a i n e d l i m e s t o n t corntinat ion ( T e ~ t
Sect icr .s 3 h 4 ) .
10. I t w i l l be necessdry t o c o n t i n u e t o moni tor t h e pe r -
formance o f t h e t e s t s e c t i o n s f o r s e v e r a l more y e a r s i n
o r d e r t o f u l l y a s s e s s t h e e f f e c t s o f environment and - t r a f f i c . -
T a b l e 1 Research O b j e c t i v e s - Group I
A. Compare i n i t i a l SN* v a l u e s f o r q u a r t z i t e i n T e s t S e c t i o n s 9 and 10 w i t h Woodbury County p r o j e c t tests. These are t h e c o n t r c l s e c t i o n s .
B. De te rmine e f f e c t of b l ? n d i n ? c o a r s e g r a i n e d l i m e s t o n e a n d q u a r t z i t e i n T e s t S e c t i o n s 3 and 4 .
C. ~ e t e r - i n e per formance o f c J a r s e g r a i n & l i m e s t u n e PMSC i n ? ' c s t S e c t i o n s 5 and 6 .
C. Determir? e f f e c t cmC b l e n d i n g f ihe g r a i n e d 11 i e s t o n e and qua r t : . i t e i n T e s r S e c i i o n s 1 an3 2.
E . V e r i f y l i n e g r a i n e d l i m e s t o n e pe r fo rmance by e x t r a p o l a t - i n g (A-D) and comparing r e s u l t s w i t h Black Hawk County p r o j e c t tests.
H . De te rmine e f f e c t o f b l e n z i n g f i n e g r a i n e d l i m e s t o n e and expanded s h a l e i n T e s t S e c t i o n s 7 and 8.
Research O b j e c t i v e s - Group I1
Kl. De te rmine t h e e f f e c t o f t r a ~ c on SN f o r q u a r t z i t e - c o n t r o l s e c t i o n s . -
K 2 . De te rmine t h e e f f e c t of t r a f f i c on SN f o r c o a r s e - g r a i n e d l i m e s t o n e - q u a r t z i t e b l e n d PMSC m i x t u r e .
K 3 . De te rmine t h e e f f e c t o f t r a f f i c on SN f o r c o a r s e g r a i n e d l i m e s t o n e PMSC m i x t u r e .
K4. Determine t h e e f f e c t o f t r a f f i c on SN f o r f i n e g r a i n e d l i m e s t o n e - q u a r t z i t e b l e n d PMSC m i x t u r e .
x5. D e t e r n i n e t h e e f f e c t o f t r a f f i c on SN f o r f i n e g r a i n e d l i m e s t o n e - expanded s h a l e PMSC m i x t u r e .
Research O b j e c t i v e s - Group I11
1. Determine e f f e c t o f t r a f f i ~ o n a s p h a l t c o n t e n t . LQ1, LQ2# M Q 1 t M Q 2 , M i , M 2 r LH1, LH2t 01, Q 2 .
2 . E s t a b l i s h mix d e s i g n c r i t e r i a f o r v a r i o u s PMSC mixes and a g g r e g a t e combina t i ons .
3 . E v a l u a t e bonding o f P9SC ( S e c t i o n s 1 and 2 ) t o P o r t l a n d cement c o n c r e t e pavement. -
*SN - S k i d Number - C o e f f i c i e n t o f f r i c t i o n a s d e t e r m i n e d by t h e l o c k e d wheel s k i d t es t t r a i l e r a s s p e c i f i e d i n ASTM E-17.
Table 2
Test Section Layout
Aggregate Evaluation - S
tory County U.S. 69 No. of Ames
Test
Actual
Actual
Section
SB
NB
Tonnage
No.
Sta. - Sta.
Sta. - Sta.
Per Cent Aggregates
%A.C.
fEPf
SB
NB
1
144+85
158+05
144+85
161+34 50% Penn. L.S.
- 50%Quartzite 5.25
EC
7?.5
72.5
2
158+05
173+08
161+34
174+76 50% Penn. L.S. - 50% Quartzite 6.25
PC
72.5
72.5
3
173+08
186+78
174+76
189+61 50% Maynes Cr. L.S.
- 50%
5.25
AC
60
72.5
Quartzite
4
186+78
200+17
189+61
202+53 50% Maynes Cr.
L.S. - 50%
6.25
AC
GO
72.5
Quartzite
5
200+17
210+65
102+53
212+80 100% Mayn s Cr L.S.
e 5.25
AC
72.5
72.5
I 6
210+65
222+37
217+32
223+18 100% Maynes'Cj 1.5.
6.25
AC
72.5
72.5 m
7
222+37
235+03
223+18
233+12 50% Penn. L.S.
- 50% Exp. Shale 6.25
AC
58
58
r
8
235+03
250130
233+12
244+47 50% Penn. L.S. - 508 Exp.
Shale 7.25
AC
66
5 8
9
250+30
261+60
244+47
263+65 100% Quartzite
5.25
AC
74.4 135.36
10
261+60
P74+60
263+65
276+85 100% Quartzite
6.25
AC
60
71.2
(CP) Existing pavement type
*BOP -
Begin project 1/2
mile south of beginning of existing A.C. surfacing.
Section 10 -
Part North
& part South of Gilbert Cor., Jct. Co.
Rd. E-23, and includes Intersection
Section Length approximately 1/4 mile
Penn.
- Pennsylvanian System -
"Argentine L.S.
Member" - Source Menlo, Id.
Quartzite -
Source -
New
Ulm
, Minn.
Mississippian System -
"Maynes Cr. L.S. Member" - S
ource -
Ferguson, Ia.
Expanded Shale H - Light Wt. Aggr.
- Source -
Centerville, Ia.
*-wed i ' .Crt~;ies
IOWA S;$J$~!~~;$!,$~~~;~IDN FN-69-5(15) --51-85 I V?I :'. !xo?-ertn S tory
lu.hd.8ldrs. ASPHALT CONCRETE MIX DESIGN L. Zearley AMES MBORATORY R.Henely
M.Stump MI.. .rp ?lax] t N i x Seal Coat s ~ z t 1/2" ~ a b . NO. ABD~-94
% d r d Us*: ~ p C c . ~ o . 7 4 3 & P ~ ~ ~ ~ ~ ~ ~ l l n e Reme4 8-8-74 - ca*, :A? I-? hot. No. ??t-69-5( 15) --21-85 cosraclor Ia. Xo&d B u i l d ~ r s 3c.
h o r . i m l o n : ~ . s . 63 Nort!i of h t = s
,... i.:T.&:k:i~s-:4enl.o Gr.&d:ii:- ('0. ; 3/e" Q u a r t z i t h chiws-New Ulm-Minn. ;7/32"
7ueiitzite-New Ii'I'n-k!inn.
8 . ~ MIS r-la -mate homlo rn : 50% UZA7'4-?98: 11.7.2 AA'i'4-391:18.7% AAT~-192
- Resul ts based on c a l c u l a t i o n s
Asphllt M ~ X . ABC - G r . of 1" specimens with 50
FIOW 0.01 In. 8 9 12 2.12 2.14 2.13 2.17
2.13 2.13 2.12
2.646 2.646 2.646 2.646
Sp. Gt.hr(h.@ ? I f . 1.025 1.025 1.025 1.025
x water Absorwloa .&ategate 0.57 0.67 0.67 0.67 I
22.4 27.6 32.8 38.1 1 Tes t Sec.#l- 5.25% 85-100 Den. asp. recommended. ", l e s t see.,$%?- 6.25% 85-100 hen. esp. recorn i i7ez
SICNLD:
8. Ortsies ASPHALT CONCRETE MIX DESIGN story
AMES UBORATORY R.C. Henely S. ~oberts G. Perrin P. ~ c ~ u f f i i Ir. Rd. ~ldg. C. Jones M. Stump
z . r r r .ndc~.ii: Plant Mix seal Coat - s i r e +" L~!I.No.BBP~ 95 -
C C ~ T Story- (to(.No. EX-69-5 (15) --21-85 comr.-tor Ioda & & ~ ~ b i w o
R.f.Cu,l,,: On U . S . - 69 North of Ai.,es &. raucts: Lst.chips-Ferquson Qr.-Marshall Co. ; Aqq.Limc-Fersuson Cr.- Ma-0
3/B"Quartzite chips-New Ulm-Minn.: 7/32"0uartzit~-~ew Uhn t w. ularanui* &rr(latc RopMians: 45% WT4-394; 5% WT4-395: 31.3% AAT4-393:
18.7% AA1'4-392
* Results based on calculations using Sp.
~ a p l u i t Mia. AaC - ;r. of 1" specimens with 50 blows on one side.
Date rested 7-9-74 7-9-74 7-9-74 7-9-74
X D r r & . lnMl r 95.00 94.00 43 .oo 92 .oo X Aiph. In Mix 5.00 6.00 7.00 8.00
Marsh11 Stablllly - Lbr. 1900 2125 1960 1633
r i o ~ - 0.01 I". 8 9 8 11 1" spec. 50 blows one 2.16 2.17 2.17 2.17 Sp.Gr. Br Dliplacemrnt Side 2.14 2.16 2.19 2.16 - sulk sp. t r . t o & . Dry AM. 2.634 2.634 2.634 2.634
Sp.Cr.Asrh.c 7 7 f . 1.025 1.025 1.025 1.025
W%s%@: G r . 2.43 2.40 2.36
X Voids 2.444 2.401 2.407 2.381
10.8- 9.5 8.2
x Waw Absorplion -®ale 0.93 0.93 0.93
X Voids in t k Mineral Assregate 22.6 23.4 24.1
X V MA. Filled with Alphalt 52.2 59.5 66.2
25.4 30.3 35.4 Test section X3 -- 5,25% 85-100 pen. zsphalt recommended
" #4 -- 6.25% 85-100 pen. asphalt SIGNED:
TABLE -; p s p h a l t Mix Desi n I.'" W
S.Roberts IWA STATE nlcHwAv CMUIS~ION FN-69-5(15) --21-85 % M I i a . i<d. Dldrs. IUATIRIALS OEPARTYLNTI Sto ry
ASPHALT CONCRETE MIX DESIGN L. Zearley AMES LABORATORY P.McGuf f i n
B.O t e s MI^. rvW class. Plant Mix Seal Coat $I,, 1/2" ~ a b . NO. AB d-@
car, . S r o n hob. NO. F!i-69-5( 15) --21-85 comnctor Iowa Road Builders Co,
ruo(.Loc.cco.: On ii,:;. ;9 Xorth of h , e s
. . Lst . a m - F e r ~ u s o n Qr. -Marshall Co. ; A m . Lime-Ferguson Qr. -Marshall
- Resul t s based on c a l c u l a t i o n s us ing Sp.
A.+II MI.. MC - r . of 1" specimens w i t h 50 blows on one: s i d e
Dale 1n1d 7-12-74 7-12-74 7-12-74 7-12-74
% Drv .lo Mlr 95.00 94.00 93.00 92.00
x ~ s p b . la Mir 5.00 6.00 7.00 8.00
MI~II SI~~I I I IV - Lbr. 2425 2375 2383 2208
ria - 0.01 la. 9 9 9 10
ggec 20 blows one s i d ? 2.18 2.19 2.23 2.25 . av bas Iaceuent 2.18 2.21 2426 2.25 lotk W.Gr.CMab. Drv A&#. 2.616 2.616 2.616. 2.616
So.Gf.As#l.e 77F. 1.025 1.025 1.025 1.025
C J ~ . W M ~ 0 . 0 . 2.47 2.44 2.40 2.37
t voids 11.9 10.2 15.2 5.0
x W M ~ ~ b s o r f f ~ a , -Asaregate 1.67 1.67 1.67 1.67
x VOYS 1s IC mlarnt a r e d a l e 20.8 21.3 20.7 20.9
x v MA. r ~ ~ l c d wnh ~ s v ) u t t 43.0 52.3 65.3 76.1
Uk.*ted Arph. film Thicknsr (Microns) 15.9 20.1 24.5 28.9 I
Test sec.!/5- 5.25% 85-100 per~.Asp. recornrnended. 36- 6.25% 85-100 pen.Asp. recommended-
SIGNED: c. k ? % h ~
- 30 - TABLE 6 A s p h a l t Mix Design S. Roberts FN-69-5 (15) --21-85 ,,, Ia. Road Bldrs. I W A S A T € HIGHWAI COYIlW1ON
IUATtRl4t.S D l t A I T I M N T I story
I w ' C. Jones L. Zearley G. Porrin ASPHALT CONCRETE MIX DESIGN R.C. Henely
AMES LABORATORY P. McGuff in -
M. Stump
*I.. T,p C~as,: Plant ~ i x Seal coat a & ~ a b . Ortgies no. ABD~-101
tmtaled US*. S,.,,o. 743 & pro~osal~,,, 8-08-74
story c a u v .- - h.,. NO. FN-69-5 (15) --21-85 co,.c,,r Road Builders co.
hd. lncalon:-. On U.S. 69 North of Ames
A*. SlWCt8: st. Chips--Menlo Qr.--Ada+r Co.: Light weight aggregate--Centervili*- -- Appanoose County -- -
F Results based on calculations using Sp Gr. nsyu l t MIX, AX - of 1" specimens with 50 blows on one s de.
oate Tnted 7-12-74 7-12-74 7-12-74 7-12-74
X Dry &. In Mix . 95.00 94.00 93 -00 92 .OO
X A8pb. In Mix 5.00 6-00 7.00 8.00
v w h r l l Uabllllv - Lba. 1442 1410 1327 1970 1 flw - 0.0% In.
1" Spec PO blows one side W.Gr. DT 0181, U N I I I ~
Bulk w. Gt. Conb. Drv M&. I Calc. h l l d Sp.Cr. 2.10 2.08 2.06 2.04
Rlce Sp. Gr. 2.03 1.97 , 1.96 X Voids
1.98 - 19.2 18.7 13.5 14.5
X water A b r w i o n -Asregale 0.70 0.70 0.70
%Voids In the minnl Aggregate 28.1 25.1 27.5
X V #A. f l t l td wlth Asphalt 28.8 33.3 46.2 47.3
Dku la ied Aspk. Film Thlcknss (Microns)
Test section #7---6.25% 85-100 pen. recommended Test section #8---7.25% 85-100 pen. recqm$#ded&-/ C. &
P".
- TABLE 'i Asph. Mix Design . B. 0 r t g i e s L. Zearley
$00 M S. Roberts l W A STATE IIIGHWAI COMMISSION I wt IUATLRIALS DIPAITMNTI FN-69-5 (15) --21-85
Ia. Rd. Bldrs. *cpHAt 1 mNSRETE MIX DESIGN S tory BORATORY R.C. Henely
.." ..... -. -"... C. Jones AMES LAL G. Per r in P. ~ c ~ u f f ih
M. stump MI. . l t p c and CI~SS: Plant Mix Sea l Coat size ~ a b . NO. ABD4-97
~mrrdcd use spec. ~ o . 7 4 3 & p r o w s a l ~ , m ew, 8/8/74
cmdr S t o m hol. N.,. FN-69-5 (15) --21-85 Cowactor Iowa Road Builders co.
h o l . . x a l , o a ~ U . S . 69 N. of Ames
-.*,,, 3/8" Q u a r t z i t e Chips - N a l m , Minnesota: 7/32" Q u a r t z i t e - New - ~ 7 - Minn. : Portland Cement F i l l e r
i d u. r-I. w w a t c rmpat lom. 60.5% AAT4-393; 37.5% AAT4-39;; 2.0% Port iand Cement---
108 MIX fOPMULA COMBtHiD GRADATION .*.. s . I" I 314" I K" I 3 R " 1 X4 1 L a 1 116 1 C30 I US0 I 8100 I #ZOO
100 43 13 5.2 4.4 3.7 3.4 3.2
- 1 1 Resul t s based on Calcula t ions us ina I
~ s p h l i t Ybr. MC . 1 Sp. G r . o f 1" specimens with 50 b l o w s on nne aide. - - - -. - - - - - -
Dale l w t d 17/10/74 7 /1on4 7fiOfV4:. 7/10/7)1
X hsph. I n Mix 5.00 6.00 7.00 8.00 1
LUtsiutl Stability - Lbs. 1033 1108 917 708 1
I FIOW - 0.01 In. I 9 9 10 12 I -- - - I" pec. 50 mow one 9 5.15
2.15 s P . t f 87 oisplacemnt s de 3 Y E 9 1~ 7 l a 2.15 I 9 11
Bulk SP. t f .Comb. Dry AM. 2.660 2.660 2.660 2.660 1 Calc.Sold Sp.Gr. 2.43 2.40 2.36
X Voids 2.45 2.40 2.40 - 11.6 10.3 9.0
Calculated Asph. Fllm T k i c k ~ c s (Yicronl) 20 0 Tes t Sec. No. 9 5.25%
10 6.25%
Table 1
1
Sk
id R
es
ista
nc
e R
es
ults
A
.C.
Re
surfa
cin
g
Re
sea
rch
(Sto
ry C
o. F
N-6
9-5
(15
)--21
-85
)
Co
ntro
l NB SB
NB SB
NB S
B
NB SB
NB SB
NB SB N_B_S~
NB
SB
NB
SB
39
40
4
0 4
0
44
4
5
42
4
4
39
42
3
8
36
4
4
45
4
5 4
4
47
4
5
44
4
4
- - --
44
4
3
41
43
4
9 4
8
48
4
9
43
4
3
45
41
4
6
47 47
45
'3
48
5
0
50
4
3
44 I
48
4
8
48
4
4
52
54
5
3 5
2
48
4
3
45
42
4
9
49
4
8
58
5
6
53
5
5
57
4
8
48
4
5 4
6
44
4
4
49
5
3
50
50
4
4
42 4
3
43
4
9
50
5
1 4
9
56
5
0
52
5
6
47
4
9
50
45
4
7
44
53
52
5
4
49
4
9
44
4
3 3
9
51
50
5
4
50
5
7
51
5
4
57
4
2
4 8
4
8
45
4
9
44
5
2 5
1
55
50
5
0 4
4
45
39
5
2 4
9
54
5
0
57
5
2
52
5
6
4 5
5
0
51
48
4
9
46
5
4 5
4
54
5
3
50
48
4
7
45
5
3
53
5
4
52
5
9
55
5
7
58
5
1
5 3
4
9
45
4
8 4
4
54
52
5
5 5
3
49
4
4
46
40
5
2
52
5
4
52
j8
5
3
55
5
7
48
5
2
47
4
6
'46 4
5
54
5
3)
5
4
52
4
8
44
4
5 4
0
2
52
58
51
5
8 5
2
52
5
6
4 7
5
2
47 4
4
46
4
5
50
52
53
52
4
8
44
4
4
44 50 59
5
2
50
5
8
53
5
2
57
5
0
5 0
4
3 5
0
43
5
4
50
54
4
3
48
4
4
50
4
2
39
4
7'4
4
9
51
'5
54
5
0
42
4
4
5 0
I
45
47
4
5
46
5
2 5
6
52
53
4
5 4
5
42
4
2
49
5
0
51
51
5
9
52
5
2
60
4
8
5 3
4
3
W
42
4
8
41
58
4
8
55
3i
49
4
1 4
7
38
4
9
48
3
7
50
40
5
4
48
5
2
51
4
3
VI
44
4
5 4
2
50
52
5
1 5
1
46
4
4
42
3
8
50
49
5
1 5
0
56
5
1
52
5
6
48
4
9
I 4
6
47
4
8
44
5
4
54
5
4
54
4
9
47
4
5 4
2
50
11
53
50
5
7
53
5
6
56
4
8
49
5
3 5
1
52
5
0
58
57
5
7
56
5
5 5
3
55
48
5
4
52
5
5 5
5
56
5
4
56
5
8
5 2
5
4
46
47
4
7
45
5
4 5
3
52
54
5
1 4
3
43
43
5
1 5
0
51
51
57
52
2
3
56
4
9
52
4
4
43
4
4
42
5
0 5
2
52
5
0
44
4
0
39
3
8
49
5
0
52
49
5
6
52
5
2
56
4
5
48
4
5 4
2
46
41
5
1 5
1
50
49
4
1 3
8
37
39
4
9
49
5
0 5
0
5d
51
54
5
5
4 4
4
9
45
44
4
2
40
4
9
49
4
9
44
4
2
36
3
8
35
47
4
8
49
4
9
52
5
0
51
5
6
45
4
8
45
41
4
2
39
4
7 5
1
49
48
3
9 3
7
37
3
6
44
4
1
51
46
5
4
48
5
3
54
4
4
4 6
4
6
46
4
5 4
2
52
54
5
2
51
4
4
42
4
3
36
4
9
51
5
4 5
e 5
6 5
1
54
5
7
4 7
4
6
47
4
6
48
43
5
1 5
3
51
52
4
3 4
3
42
3
9
48
5
0
54
4
8
58
51
5
5
59
4
9
51
5
0 4
8
52
42
5
5 5
2
55
52
5
6
39 4
3 3
7
50
52
5
3
50
5
9
55
5
6
58
4
7
46
- 36 - NON-PARTICIPATING PROGRESS RECORD SAMPLE Aaphal 4- I m Ehta Highway Cornmiusion R.C.Henely
FN-69-5(15)--21-85 M A S L I ( W D E P ~ story Co.
BIWIT - MISCELLANEOUS MATlCRUIB P'McGuf Anzs LABOrnntBY
TABLE 12
I1lMl(lt Asphalt AC 851100 Lbontcq NO, AB4-128
Lt.sdd Teat Section
orracr Srnrr Rnj No FN-69-5(15)--21-85
kohrr American Oil - ContnctDr Iowa Road Builders
UlndIIptsNl Sampled from valve on plant
- specific Gravity at 6 0 ~ ~ / 6 0 ~ F . ----------------- Soft. Point: Method (R & 81 ------------------- OF.
pentration at 77'~. 100 ~ m s . 5 sec. ------------ 98
flash point .................................... OF.
Soluble in Trichloroethylene ------------------- 99.95 %
Ductility at 770~. ............................. 13C-t Cms'
Spot Test ......................................
Thin Film Msa on ~eafrng 5 Hrs. at 32S°F. ------ 0.02 %
Penetration of Xes. at 77°F.100 Gms. 5 Sec. ---- 64
% Original Penetration (Thin Film Res.) -------- 65
Ductility at 77OF. (Thin Film Res.) ------------ 13Ot cms . * ~ b ~ ~ l ~ t ~ viscosity , original----------------------------- 848
~ b ~ ~ l ~ t ~ viscosity, T.F.---------------------------------- 1675
Jw----- Complies
J L: LA----
slcr*a T a c h w=
APPENDIX A
--*.--.. --
---...-
-.*a*- .-...-
. . . .
-. - - - . . . . . . . - . . . . . . . .
city